I am thinking of an AR-15 and want one just to have. I dont want to build one, just off the shelf. I see a Bushmaster at Walmart for about 900.00. It has the sites that double as a handle, thats the style I want so I can add a site latter. Is there one as good at a better price? What brand? What brand and type of after market site would be goos as an add on. Thanks